Projector with narrow-spectrum light source to complement broad-spectrum light source

ABSTRACT

A projector that has a narrow-spectrum light source to complement a broad-spectrum light source is disclosed. The broad-spectrum light source has a broad spectrum. The narrow-spectrum light source has a narrow spectrum complementing the broad spectrum of the broad-spectrum light source.

RELATED APPLICATIONS

The present patent application is a continuation of the previously filedand patent application entitled “Project with Narrow Spectrum LightSource to Complement Broad-Spectrum Light Source”, filed on May 3, 2002,and assigned Ser. No. 10/138,590 now U.S. Pat. No. 6,733,139, which is acontinuation-in-part of the previously filed and copending patentapplication entitled “Multi-Source LCD Backlight for White BalanceAdjustment”, filed on Jun. 5, 2000, and assigned Ser. No. 09/587,446,and now abandoned.

BACKGROUND OF THE INVENTION

Projectors are generally devices that integrate light sources, opticssystems, electronics, and displays for projecting images from computersor video devices onto walls or screens, for large-image viewing. Theyare especially popular among business users who give presentations aspart of their job responsibilities. Newer projectors can weigh as littleas a few pounds, making them well suited for business travelers. As thequality of projection technology has improved, projectors are alsofinding their way into peoples' homes for high-definition television(HDTV) and other home entertainment applications. Some industry punditspredict that digital projectors will also become the standard projectiontechnology used in movie theaters.

The light sources utilized in projectors are an integral factor in theresulting quality of the projected image. A light source is desirablysmall in size, long lasting, and uniform in the light that it produces.Until recently, most projectors relied on metal halide lamps that employa spark across a gas-filled gap to create light. However, metal halidelamps tended to have color and luminance stability problems, and tendedto deposit materials on their sidewalls during operation, resulting inreduced brightness. More recently, some projectors have been using ultrahigh pressure (UHP) arc lamps. These lamps use an arc in a pure mercuryvapor under high pressure. The arc gap is much smaller than thegas-filled gap of a metal halide lamp, resulting in greater lightingefficiency. Small amounts of oxygen and halogen are usually mixed withthe mercury vapor, helping to remove material deposits from a lamp'ssidewalls, which maintains the lamp's brightness substantiallythroughout its lifetime.

However, UHP mercury-vapor arc lamps, as well as other types of lampsused in projectors, still suffer from some drawbacks. Arc lamps, forinstance, usually output less light at red wavelengths than they do atother wavelengths. This means that parts of the images being projectedthat rely on red wavelengths of light for rendering may not appear asbright, or may appear inaccurate as compared to how they should appear.Arc lamps may also have uneven color intensities. For instance, thelight output at blue wavelengths, or at green wavelengths, may only beable to be produced at deep or dull tones. This means that parts of theimages being projected that rely on these wavelengths of light forrendering may appear dull, or may also appear inaccurate as compared tohow they should appear.

For these and other reasons, therefore, there is a need for the presentinvention.

SUMMARY OF THE INVENTION

The invention relates to a projector that has a narrow-spectrum lightsource to complement a broad-spectrum light source. The broad-spectrumlight source has a broad spectrum. The narrow-spectrum light source hasa narrow spectrum complementing the broad spectrum of the broad-spectrumlight source.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings referenced herein form a part of the specification.Features shown in the drawing are meant as illustrative of only someembodiments of the invention, and not of all embodiments of theinvention, unless otherwise explicitly indicated, and implications tothe contrary are otherwise not to be made.

FIG. 1 is a block diagram of a general projection system according to anembodiment of the invention that includes a broad-spectrum light sourceand a narrow-spectrum light source.

FIGS. 2A and 2B are diagrams illustrating two different types of partialspectral deficiencies of a broad-spectrum light source, according tovarying embodiments of the invention.

FIGS. 3A and 3B are diagrams illustrating how use of a narrow-spectrumlight source can compensate for and substantially correct the partialspectral deficiencies of FIGS. 2A and 2B, respectively, according tovarying embodiments of the invention.

FIG. 4 is a cross-sectional side-view diagram of a projection systemaccording to a specific embodiment of the invention in whichnarrow-spectrum light is combined with broad-spectrum light beforepassing through a rotatable color wheel.

FIG. 5 is a front-view diagram of the narrow-spectrum light source ofFIG. 4, according to an embodiment of the invention.

FIGS. 6A and 6B are front-view diagrams of different types of rotatablecolor wheels that can be used as the rotatable color wheel of FIG. 4,according to varying embodiments of the invention.

FIGS. 7A and 7B are diagrams of graphs showing light before it enters anintegration rod, such as that of FIG. 4, and after it leaves theintegration rod, respectively, according to an embodiment of theinvention.

FIG. 8 is a flowchart of a method of use according to an embodiment ofthe invention that is consistent with the system of FIG. 4.

FIG. 9 is a cross-sectional side-view diagram of a projection systemaccording to another specific embodiment of the invention in whichnarrow-spectrum light is combined with broad-spectrum light after thebroad-spectrum light has passed through a rotatable color wheel.

FIG. 10 is a flowchart of a method of use according to an embodiment ofthe invention that. is consistent with the system of FIG. 9.

FIG. 11 is a flowchart of a method of manufacture according to anembodiment of the invention that is consistent with the systems of FIGS.4 and 9.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description of exemplary embodiments of theinvention, reference is made to the accompanying drawings that form apart hereof, and in which is shown by way of illustration specificexemplary embodiments in which the invention may be practiced. Theseembodiments are described in sufficient detail to enable those skilledin the art to practice the invention. Other embodiments may be utilized,and logical, mechanical, and other changes may be made without departingfrom the spirit or scope of the present invention. The followingdetailed description is, therefore, not to be taken in a limiting sense,and the scope of the present invention is defined only by the appendedclaims.

Overview

FIG. 1 shows a block diagram of a projection system 100 according to anembodiment of the invention. The system 100 may be implemented as aprojector. The projection system 100 includes a broad-spectrum lightsource 102, a narrow-spectrum light source 104, a spatial lightmodulator (SLM) 106, projection optics 108, and a screen 110. The system100 also includes light source optics 105, an image source 107, and animage controller 109. The broad-spectrum light source 102 outputs lightat a broad spectrum, and can be considered a means for emitting suchlight. It may be an ultra high pressure (UHP) mercury vapor arc lamp, oranother type of broad-spectrum light source. By comparison, thenarrow-spectrum light source 104 outputs light within a narrow spectrum,and can be considered a means for emitting such light. It may be one ormore light-emitting diodes (LED's), or another type of narrow-spectrumlight source. A narrow spectrum is generally defined as only a portionof the visible light spectrum. By comparison, a broad spectrum issubstantially, but not necessarily completely, the visible lightspectrum.

The light source optics 105 process the light output by the lightsources 102 and 104 for output to the SLM 106. The image controller 109prepares an image signal received from the image source 107 for outputto the SLM 106. The image source 107 may be a computer, a video device,and so on. The image may be a still image or a moving image. The SLM 106in turn modulates the light output by both the broad-spectrum lightsource 102 and the narrow-spectrum light source 104, as received throughthe light source optics 105, in accordance with the desired image, asreceived through the image controller 109. The SLM may be aliquid-crystal display (LCD) SLM, a digital light processing (DLP) SLM,or another type of SLM. In the case of a DLP SLM, the SLM may morespecifically be a digital micromirror display (DMD).

The broad-spectrum light source 102 outputs broad-spectrum light thatlikely suffers from a partial (i.e., narrow) spectral power deficiency.Broad-spectrum light is generally and non-restrictively defined as lightthat has wavelengths substantially across the entire visible lightspectrum. Thus, the broad-spectrum light source 102 is a light sourcethat can generate light having wavelengths substantially across theentire visible light spectrum. A partial spectral power deficiency iswhere the light has a power deficiency in at least a part of thespectrum of light output. The partial spectral power deficiency may morespecifically be one of at least two different defects, among others.First, the light output may not be as bright in one part of the spectrumas compared to the other spectral parts. Second, the light output maynot have as high a color intensity in one spectral part as compared tothe other parts.

FIG. 2A shows a graph 200 illustrating a partial spectral deficiency inwhich the light output is not as bright in one spectral part as comparedto other spectral parts. The graph 200 of FIG. 2A, like all other graphsof this patent application, is an idealized representation, and is notmeant as an actual representation. That is, the graphs of this patentapplication are for illustrative purposes only. The axis 201 measuresbrightness. The spectrum has three chief parts, a red part 202, a greenpart 204, and a blue part 206. The line 208 indicates the brightness ofthe light output across these spectral parts. The dotted line 210indicates a threshold brightness level that is desired across the entirespectrum. As shown in FIG. 2A, the light output falls below thethreshold brightness level at the red wavelengths within the redspectral part 202. That is, there is a partial spectral deficiency atred wavelengths of light.

FIG. 2B shows a color intensity chart 250 illustrating a partialspectral deficiency in which the light output has a color intensity thatis not as high in one spectral part as compared to other spectral parts.The chart 250 has a center 258 corresponding to a low color intensitythat increases radially therefrom to a high color intensity indicated bythe outside circle 260. The spectrum has three chief parts, a red part252, a green part 254, and a blue part 256. The triangle 264 representsthe color intensity of the light output across these spectral parts. Thedotted circle 262 indicates a threshold color intensity level that isdesired across the entire spectrum. As shown in FIG. 2B, the lightoutput falls below the threshold color intensity level at the greenwavelengths within the green spectral part 254. That is, there is apartial spectral deficiency at green wavelengths of light. There mayalso be a partial spectral deficiency at other wavelengths of light,such as at blue wavelengths of light, and so on.

The narrow-spectrum light source 104 of FIG. 1 outputs narrow-spectrumlight that has a narrow spectrum complementing the broad spectrum of thebroad-spectrum light source 102 of FIG. 1. Narrow-spectrum light isgenerally and non-restrictively defined as light that has wavelengths inonly a part of the visible spectrum. For instance, the narrow-spectrumlight may have only the red wavelengths of the visible spectrum, thegreen wavelengths of the visible spectrum, or the blue wavelengths ofthe visible spectrum, and so on. Thus, the narrow-spectrum light source104 is a light source that can generate light having wavelengths only ina part of the visible light spectrum. This narrow spectrum preferablycorresponds to the partial spectral deficiency of the broad spectrum ofthe broad-spectrum light source 102. That is, the light output by thenarrow-spectrum light source 104 may have a brightness at a narrowspectrum compensating for lower brightness at a part of this broadspectrum, or a high color intensity at a narrow spectrum compensatingfor a lower color intensity at a part of this broad spectrum, and so on.

FIG. 3A shows a graph 300 illustrating how the narrow spectrum of lightcompensates for and corresponds to the partial spectral deficiency ofthe broad spectrum of light in terms of brightness, according to anembodiment of the invention. As before, the axis 201 measuresbrightness, and there are three primary spectral parts, a red part 202,a green part 204, and a blue part 206. The line 208 indicates thebrightness of the broad-spectrum light across these spectral parts. Thedotted line 210 indicates a threshold brightness level that is desiredacross the entire spectrum. The line 208 falls below the dotted line 210primarily at the red spectral part 202.

The line 302 of FIG. 3A indicates the brightness of the narrow-spectrumlight across the spectral parts 202, 204, and 206. As a result of itsnarrow spectrum, the light only is output at one spectral part, the redspectral part 202, and not at the green part 204 or at the blue part206. The brightness of the narrow-spectrum light at the red spectralpart 202, however, is greater than the threshold level indicated by thedotted line 210. Thus, combining the narrow-spectrum light indicated bythe line 302 with the broad-spectrum light indicated by the line 208yields the horizontal line 304, which represents light having abrightness level greater than the threshold level across the entirespectrum. In this way, the narrow spectrum of light compensates for andcorresponds to the partial spectral deficiency of the broad spectrum oflight in one embodiment of the invention.

FIG. 3B shows a color intensity chart 350 illustrating how the narrowspectrum of light compensates for and corresponds to the partialspectral deficiency of the broad spectrum of light in terms of colorintensity, according to another embodiment of the invention. As before,there is a chart center 258 correlating with a low color intensity thatincrease radially therefrom to a high color intensity indicated by theoutside circle 260. The spectrum has three primary parts, a red part252, a green part 254, and a blue part 256. The dotted circle 262indicates a threshold color intensity level that is desired across theentire spectrum. The triangle 264 represents the color intensity of thebroad-spectrum light output across the spectrum, where there is apartial spectral deficiency at the green spectral part 254, at which thecolor intensity is undesirably low.

The triangle 354 of FIG. 3B indicates the color intensity of thenarrow-spectrum light across the spectral parts 252, 254, and 256. As aresult of its narrow spectrum, the light is substantially output only atone spectral part, the green spectral part 254, and not at the redspectral part 252 or at the blue spectral part 256. The color intensityof the narrow-spectrum light at the green spectral part 254, however, ishigher than the threshold level indicated by the dotted circle 262.Thus, combining the narrow-spectrum light indicated by the triangle 354with the broad-spectrum light indicated by the triangle 264 yields thetriangle 352, which represents light having a color intensity higherthan the threshold level across the entire spectrum. In this way, thenarrow spectrum of light compensates for and corresponds to the partialspectral deficiency of the broad spectrum of light in one embodiment ofthe invention.

The broad-spectrum light source 102 of FIG. 1 can be considered aprimary light means, whereas the narrow-spectrum light source 104 can beconsidered a compensatory light means. The primary light means is forproviding light that has a broad spectrum, but that which is weak at aportion, such as a narrow portion, of the broad spectrum. Thecompensatory light means is for compensating for the narrow portion ofthe broad spectrum at which the light is weak. The part of the broadspectrum at which the light is weak may be, for example, the redspectral part, the green spectral part, or the blue spectral part, amongother parts of the spectrum. It may be weak in terms of lightbrightness, color intensity, and so on.

First Specific Embodiment of Projection System

FIG. 4 shows a cross-sectional side profile of a system 400 according toan embodiment of the invention. The system 400 is consistent with thesystem 100, and shows the system 100 in more detail in accordance with aspecific embodiment of the invention. The broad-spectrum light source102 is preferably optically centered within the reflector 402, which isat least substantially elliptical in shape. The reflector 402, and otherreflectors of the invention, may have other shapes as well. Thebroad-spectrum light source 102 may also be considered the primary lightsource. The narrow-spectrum light source 104 preferably includes a ringof LED's centered around the broad-spectrum light source 102. FIG. 5shows a front view of the narrow-spectrum light source 104 in such aninstance. The narrow-spectrum light source 104 may also be consideredthe secondary light source. The narrow-spectrum light source 104 may besaid to be adjacent to the broad-spectrum light source 102, although thepositioning of the former to the latter as shown in FIG. 4 is oneexample of such adjacency.

Referring back to FIG. 4, the light from the narrow-spectrum lightsource 104 is combined with the light from the broad-spectrum lightsource 102 before proceeding through the light source optics 105. As hasbeen described, the broad-spectrum light source 102 has a partialspectral deficiency that is compensated for by the narrow-spectrum lightsource 104. Thus, this compensation or correction takes place prior toany light from the narrow-spectrum light source 104 or from thebroad-spectrum light source 102 reaching the light source optics 105.The light source optics 105 in the system 400 includes a condenser lens404, a rotatable color wheel 406, an integration rod 408, and acollimating lens 410. The condenser lens 104 and/or the collimating lens410 can be comprised of single or multiple glass elements.

The condenser lens 404 focuses the combined light from thebroad-spectrum light source 102 and the narrow-spectrum light source104, as reflected by the elliptical reflector 402. The condenser lens404 specifically focuses this light through the rotatable color wheel406, which rotates into and perpendicular to the plane of FIG. 4, asindicated by the arrow 407. The color wheel 406 is used to pass throughlight of a particular color at a given time, such that at that time onlythe parts of the image to be projected having that color are displayed.That is, the system 400, instead of creating red, green, and blue imagesat the same time and combining them optically, creates the red, green,and blue images at different times, relying on the viewer's visualsystem to recombine them.

FIGS. 6A and 6B show front views of different color wheels 406. Thecolor wheel 406 of FIG. 6A is divided into three equal portions, a redportion 602, a green portion 604, and a blue portion 606. When the redportion 602 is incident to the combined light from the broad-spectrumlight source 102 and the narrow-spectrum light source 104, then only thered wavelengths are passed. Similarly, when the green portion 604 or theblue portion 606 is incident to the combined light from the lightsources 102 and 104, only the green or blue wavelengths, respectively,are passed. The color wheel 406 of FIG. 6B is similar to that of FIG.6A, except that half of the wheel 406 is reserved for a clear portion608, whereas the other half of the wheel 406 is divided into the redportion 602, the green portion 604, and the blue portion 606.

Referring back to FIG. 4, the combined light passing through the colorwheel 406 next passes through the integration rod 408. The integrationrod 408 renders the combined light more uniform. The integration rod 408may also be referred to as a light pipe. FIGS. 7A and 7B showapproximations of how light approaching the integration rod 408 appears,and how light leaving the integration rod 408 appears, respectively. InFIG. 7A, the graph 700 shows a line 702 representative of the brightnessof the light over a distance, prior to the light reaching theintegration rod 408. The light is brighter at the center than at theends. By comparison, in FIG. 7B, the graph 750 shows a line 752representative of the brightness of the light over the distance afterthe light has passed through the integration rod 408. The light isuniformly bright across the entire cross-sectional distance.

Referring back to FIG. 4, once the combined light passes through theintegration rod 408, it passes through the collimating lens 410, whichcollimates the light before it reaches the SLM 106. The SLM 106 isconfigured by the image controller 109 based on the desired imagereceived from the image source 107. Specifically, the SLM 106 isconfigured based on the current color of the light that the color wheel406 has passed. For example, if the color wheel 406 passed only redlight, then the SLM 106 is configured in accordance with the red partsof the desired image. As another example, if the color wheel 406 passesall light through a clear portion thereof, then the SLM 106 isconfigured in accordance with all color parts of the desired image. Thelight thus reflects off the SLM 106 and transmits through the projectionoptics 108 that focus the light onto the screen 110, on which viewerssee the desired image.

The system 400 therefore combines the compensatory light of thenarrow-spectrum light source 104 with the broad-spectrum light of thebroad-spectrum light source 102 prior to the then-combined light passingthrough the color wheel 406. This approach to utilizing a narrowspectrum of light to compensate for a partial spectral deficiency in abroad spectrum of light is preferably employed when the partial spectraldeficiency relates to light brightness. Where the broad spectrum oflight has a spectral part at which it is not as bright as desirable,utilizing a corresponding narrow spectrum of light can be accomplishedas shown in FIG. 4 to add to this brightness and yield more uniformbrightness across the entire visible light spectrum.

FIG. 8 shows a method 800 according to an embodiment of the invention.The method 800 is specifically a method of use for systems like thesystem 400 of FIG. 4 that has been described, among other systems.First, broad-spectrum light is provided by a broad-spectrum light source(802), and narrow-spectrum light is provided by a narrow-spectrum lightsource (804). The narrow-spectrum light complements the broad-spectrumlight as has been described. The narrow-spectrum light is combined withthe broad-spectrum light (806).

The narrow-spectrum light may be particularly adjusted to properlycompensate for the partial spectral deficiency of the broad-spectrumlight (808). This may be accomplished by the projector or projectionsystem itself, or by user adjustment of controls provided on theprojector or projection system. For instance, in the former case, abrightness sensor may determine the brightness of the narrow spectrumand compare it to the brightness of the broad spectrum as a whole. Ifthe brightness of the narrow spectrum is greater than the desiredbrightness relative to the brightness of the broad spectrum, then thenarrow-spectrum light output is decreased, and so on. In the case wherethe narrow-spectrum light source is a number of LED's, increasing ordecreasing the brightness of the narrow-spectrum light may beaccomplished by turning on or off more LED's, respectively.

Next, the combined light is output through light-source optics, such asa condenser lens, a rotatable color wheel, an integration rod, and acollimating lens (810), as has been described. Thereafter, the combinedlight is output through an SLM in accordance with a desired image, andprojected through projection optics onto a screen for viewing (812). Inthis way, the method 800 achieves projection by combiningnarrow-spectrum light with broad-spectrum light so that the formercompensates for weakness in the latter. Weakness is generally definedherein as having a reduced or lower than desired intensity for a rangeof wavelengths.

Finally, at some point, the narrow-spectrum light source may fail (814).If not, then the method 800 is finished (816). However, if thenarrow-spectrum light source does fail, then the processing of thecombined light by the SLM may be adjusted to attempt to compensate forthis failure (818). That is, the SLM may be adjusted by the imagecontroller to attempt to compensate for the failure of thenarrow-spectrum light source. For example, the other parts of thespectrum at which the broad-spectrum light source is not deficient maybe artificially decreased in brightness level so that uniform brightnessis still achieved across the entire spectrum, albeit not at the desiredbrightness level, and so on.

Second Specific Embodiment of Projection System

FIG. 9 shows a cross-sectional side profile of a system 900 according toanother embodiment of the invention. The system 900 is consistent withthe system 100, and shows the system 100 in more detail in accordancewith a specific embodiment of the invention. The broad-spectrum lightsource 102 is again preferably optically centered within the reflector402, which is at least substantially elliptical in shape. Thebroad-spectrum light source 102 may be considered the primary lightsource. The narrow-spectrum light source 104 is located away from thebroad-spectrum light source 102, outside of the reflector 402. Thenarrow-spectrum light source 104 may also be considered the secondarylight source.

Thus, only the light from the broad-spectrum light source 102 passesthrough the condenser lens 404 and the color wheel 406 components of thelight source optics 105. As before, the condenser lens 404 focuses thelight through a portion of the color wheel 406, which rotates into andperpendicular to the plane of FIG. 9, as indicated by the arrow 407. Thecolor wheel 406 may be a color wheel such as has already been shown inand described in conjunction with FIGS. 6A and 6B, or another type ofcolor wheel. The light from the broad-spectrum light source 102, afterpassing through the condenser lens 404 and the color wheel 406, reachesthe integration rod 408.

The light from the narrow-spectrum light source 104 is optically routed,preferably via fiber optics 902, to the integration rod 408 as well.Thus, at the integration rod 408 the broad-spectrum light is combinedwith the narrow-spectrum light. Preferably, but not necessarily, thelight from the narrow-spectrum light source 104 is in sync with thecolor wheel 406, such that the light source 104 emits light when thecolor wheel 406 has turned to the color at which the broad-spectrumlight source 102 is partially deficient. The integration rod 408 servesto render the cross-section of the combined light uniform, as hasalready been shown in and described in conjunction with FIGS. 7A and 7B.The combined light then passes through the collimating lens 410, whichcollimates the light before it reaches the SLM 106. The SLM 106 isconfigured by the image controller 109 based on the desired imagereceived from the image source 107. As before, the SLM 106 isspecifically configured based on the current color of the light that thecolor wheel 406 has passed. The light thus reflects off the SLM 106 andthrough the projection optics 108 that focus it onto the screen 110 onwhich viewers see the desired image.

The system 900 therefore combines the compensatory light of thenarrow-spectrum light source 104 with the broad-spectrum light of thebroad-spectrum light source 102 after the broad-spectrum light haspassed through the condenser lens 404 and the color wheel 406. Thisapproach to utilizing a narrow spectrum of light to compensate for apartial spectral power deficiency is preferably employed when thepartial spectral deficiency relates to color intensity. Where the broadspectrum of light has a spectral part at which its color intensity isnot as high as desirable, utilizing a corresponding narrow spectrum oflight can be accomplished as shown in FIG. 9 to add to this colorintensity and yield a more uniform color intensity across the entirevisible light spectrum.

FIG. 10 shows a method 1000 according to an embodiment of the invention.The method 1000 is specifically a method of use for systems like thesystem 900 of FIG. 9 that has been described, among other systems.First, broad-spectrum light is provided by a broad-spectrum light source(1002), and narrow-spectrum light is provided by a narrow-spectrum lightsource (1004). The broad-spectrum light is output through a condenserlens and a rotatable color wheel (1006), and thereafter combined withthe narrow-spectrum light (1008). As has been described, thenarrow-spectrum light may be particularly adjusted to properlycompensate for the partial spectral power deficiency of thebroad-spectrum light (1010).

The combined light is then output through an integration rod andcollimating lens (1012), and then through an SLM in accordance with adesired image and focused through projection optics onto a screen forviewing (1014). As before, at some point the narrow-spectrum lightsource may fail (1016). If not, then the method 1000 is finished (1018).However, if the narrow-spectrum light source does fail, then theprocessing of the combined light by the SLM may be adjusted to attemptto compensate for this failure (1020), as has been described.

Method of Manufacture of Projection System

FIG. 11 shows a method 1100 according to an embodiment of the invention.The method 1100 may be substantially utilized to manufacture a projectoror projection system according to an embodiment of the invention as hasbeen described. This may include the system 100 of FIG. 1, the system400 of FIG. 4, the system 900 of FIG. 9, or another system according toan embodiment of the invention. The order of 1102, 1104, 1106, 1108, and1110 as shown in FIG. 11 may vary. First, a primary light source havinga broad spectrum is provided (1102), and a secondary light source havinga narrow spectrum complementing the broad spectrum is provided (1104).

The secondary light source is positioned relative to the primary lightsource so that the light provided by the latter is combined with thelight provided by the former (1106). This may be accomplished by, forexample, positioning the secondary light source adjacent to the primarylight source. As another example, fiber optics may be used to opticallyroute the secondary light source wherever it is positioned so that itslight can be combined with the light of the primary light source.

Next, light source optics, such as a condenser lens, a rotatable colorwheel, an integration rod, and a collimating lens, are positioned(1108). The rotatable color wheel and the integration rod mayspecifically be positioned so that the light provided by the primarylight source as combined with the light provided by the secondary lightsource pass through both of these light source optics components.Alternatively, the color wheel and the integration rod may be positionedso that the light provided by the primary light source passes throughthese components by itself, before combination with the light providedby the secondary light source. Finally, an SLM and projection optics arepositioned (1110), so that the combined light passes through theSLM—that is, reflects off the SLM—and passes through the projectionoptics that focus it for display.

Conclusion

It is noted that, although specific embodiments have been illustratedand described herein, it will be appreciated by those of ordinary skillin the art that any arrangement is calculated to achieve the samepurpose may be substituted for the specific embodiments shown. Forexample, other applications and uses of embodiments of the invention,besides those described herein, are amenable to at least someembodiments. This application is intended to cover any adaptations orvariations of the present invention. Therefore, it is manifestlyintended that this invention be limited only by the claims andequivalents thereof.

1. An electronic device comprising: a broad-spectrum light source havinga broad spectrum; and, a narrow-spectrum light source having a narrowspectrum complementing the broad spectrum of the broad-spectrum lightsource.
 2. The electronic device of claim 1, wherein the broad spectrumof the broad-spectrum light source has a partial spectral powerdeficiency, and the narrow spectrum of the narrow-spectrum light sourcecorresponds to the partial spectral power deficiency.
 3. The electronicdevice of claim 2, wherein the broad-spectrum light source outputs lightgreater than a threshold brightness level throughout the broad spectrumexcept at a part of the broad spectrum at which the partial spectralpower deficiency exists.
 4. The electronic device of claim 3, whereinthe narrow-spectrum light source outputs light at the part of the broadspectrum at which the partial spectral power deficiency of thebroad-spectrum light source exists greater than the threshold brightnesslevel.
 5. The electronic device of claim 2, such that light output bythe broad-spectrum light source in combination with light output by thenarrow-spectrum light source is greater than a threshold brightnesslevel throughout the broad spectrum.
 6. The electronic device of claim2, wherein the partial spectral deficiency comprises a red spectralpower deficiency.
 7. The prejeeter electronic device of claim 1, whereinthe narrow spectrum of the narrow-spectrum light source has a high colorintensity corresponding to a low color intensity of the broad spectrumof the broad-spectrum light source.
 8. The electronic device of claim 7,wherein the broad-spectrum light source outputs light having a colorintensity greater than a threshold color intensity level throughout thebroad spectrum except at a part of the broad spectrum having the lowcolor intensity.
 9. The electronic device of claim 8, wherein thenarrow-spectrum light source outputs light having the high colorintensity greater than the threshold color intensity level at the partof the broad spectrum at which the light output by the broad-spectrumlight source has the low color intensity.
 10. The electronic device ofclaim 7, such that light output by the broad-spectrum light source incombination with light output by the narrow-spectrum light source has acolor intensity greater than a threshold color intensity levelthroughout the broad spectrum.
 11. The electronic device of claim 7,wherein the low color intensity comprises one of a low blue intensityand a low green intensity.
 12. The electronic device of claim 1, whereinthe broad-spectrum light source comprises an ultra-high-pressure (UHP)mercury-vapor arc lamp.
 13. The electronic device of claim 1, whereinthe narrow-spectrum light source comprises at least one light-emittingdiode (LED).
 14. An electronic device comprising: a primary light meansfor providing light having a broad spectrum, the light being weak at anarrow part of the broad spectrum; and, a compensatory light means forcompensating for the narrow part of the broad spectrum at which thelight is weak.
 15. The electronic device of claim 14, wherein the lightis weak at the narrow part of the broad spectrum in that a brightness ofthe light is weak at the narrow part of the broad spectrum.
 16. Theelectronic device of claim 15, wherein the narrow part of the broadspectrum comprises a red spectral part of the broad spectrum.
 17. Theelectronic device of claim 14, wherein the light is weak at the narrowpart of the broad spectrum in that a color intensity of the light isweak at the narrow part of the broad spectrum.
 18. The electronic deviceof claim 17, wherein the narrow part of the broad spectrum comprises oneof a blue spectral part and a green spectral part of the broad spectrum.19. The electronic device of claim 14, wherein the primary light meanscomprises an ultra-high-pressure (UHP) mercury-vapor arc lamp, and thecompensatory light means comprises at least one light-emitting diode(LED).
 20. An electronic device comprising: a reflector; a primary lightsource positioned within the reflector and outputting light with a broadspectrum; and, a secondary light source positioned outside the reflectorand outputting light with a narrow spectrum and optically routed forcombination with the light output by the primary light source.
 21. Theelectronic device of claim 20, wherein the broad spectrum of the lightoutput by the primary light source has a narrow spectral powerdeficiency to which the narrow spectrum of the light output by thesecondary light source corresponds.
 22. The electronic device of claim21, wherein the narrow spectral deficiency is one of a light brightnessdeficiency at the narrow spectrum and a color intensity deficiency atthe narrow spectrum.
 23. The electronic device of claim 20, furthercomprising fiber optics to optically route the light output by thesecondary light source for combination with the light output by theprimary light source.
 24. An electronic device comprising: means foremitting first light having a broad spectrum; and, means for emittingsecond light having a narrow spectrum complementing the broad spectrumof the first light.
 25. The electronic device of claim 24, wherein thebroad spectrum has a partial spectral power deficiency, and the narrowspectrum corresponds to the partial spectral power deficiency.
 26. Theelectronic device of claim 24, wherein the narrow spectrum has a highcolor intensity corresponding to a low color intensity of the broadspectrum.
 27. A method for performance in conjunction with an electronicdevice comprising: providing light by a broad-spectrum light sourcehaving a broad spectrum; providing light by a narrow-spectrum lightsource having a narrow spectrum complementing the broad spectrum of thebroad-spectrum light source; and, combining the light provided by thebroad-spectrum light source with the light provided by thenarrow-spectrum light source.
 28. The method of claim 27, furthercomprising adjusting the light provided by the narrow-spectrum lightsource to compensate for a partial spectral power deficiency of thebroad spectrum of the light provided by the broad-spectrum light source,the narrow spectrum of the light provided by the narrow-spectrum lightsource corresponding to the partial spectral power deficiency.
 29. Themethod of claim 27, further comprising adjusting the light provided bythe narrow-spectrum light source to compensate for a low color intensityof the broad spectrum of the light provided by the broad-spectrum lightsource, the narrow spectrum of the light provided by the narrow-spectrumlight source having a high color intensity corresponding to the lowcolor intensity of the broad spectrum of the light provided by thebroad-spectrum light source.
 30. A method for performance in conjunctionwith an electronic device comprising: providing a primary light sourcehaving a broad spectrum; providing a secondary light source having anarrow spectrum complementing the broad spectrum of the primary lightsource; and, positioning the secondary light source relative to theprimary light source so that light provided by the primary light sourceis combined with light provided by the secondary light source.
 31. Themethod of claim 30, wherein positioning the secondary light sourcerelative to the primary light source comprises positioning the secondarylight source outside a reflector in which the primary light source ispositioned and optically routing the light provided by the secondarylight source for combination with the light provided by the primarylight source.
 32. An electronic device comprising: a light source of afirst type; and, a light source of a second type, a spectrum of thelight source of the second type complementing a spectrum of the lightsource or the first type.
 33. The projection system of claim 32, whereinthe spectrum of the light source of the first type is broad, and thespectrum of the light source of the second type is narrow.
 34. Theprojection system of claim 32, wherein the first type is anultra-high-pressure (UHP) mercury-vapor arc lamp type.
 35. Theprojection system of claim 32, wherein the second type is alight-emitting diode (LED) lamp type.
 36. A narrow-spectrum light sourcefor use in an electronic device having a primary broad-spectrum lightsource, the narrow-spectrum light source having a narrow spectrumcomplementing a broad spectrum of the broad-spectrum light source. 37.The narrow-spectrum light source of claim 36, wherein the narrowspectrum of the narrow-spectrum light source corresponds to a partialspectral power deficiency of the broad spectrum of the broad-spectrumlight source.
 38. The narrow-spectrum light source of claim 36, whereinthe narrow spectrum of the narrow-spectrum light source has a high colorintensity corresponding to a low color intensity of the broad spectrumof the broad-spectrum light source.
 39. The narrow-spectrum light sourceof claim 36, wherein the narrow-spectrum light source includes one ormore light-emitting diodes (LED's).
 40. A broad-spectrum light sourcefor use in an electronic device having a narrow-spectrum light source,the broad-spectrum light source having a broad spectrum, thenarrow-spectrum light source having a narrow spectrum complementing thebroad spectrum of the broad-spectrum light source.
 41. Thebroad-spectrum light source of claim 40, wherein the broad spectrum ofthe broad-spectrum light source has a partial spectral power deficiencyto which the narrow spectrum of the narrow-spectrum light sourcecorresponds.
 42. The broad-spectrum light source of claim 40, whereinthe broad spectrum of the broad-spectrum light source has a low colorintensity to which a high color intensity of the narrow spectrum of thenarrow-spectrum light source corresponds.
 43. The broad-spectrum lightsource of claim 40, wherein the broad-spectrum light sources includes anultra-high-pressure (UHP) mercuy-vapor arc lamp.